The Design Of HD Video Encoder

Released jointly by International Organization for Standardization and International Telecommunication Union after the MPEG-4 digital video compression format, H.264 does not only retain the advantages and essence of former compression technology, but also possess many new features which are beyond other compression techniques. The current problems facing the encoder are not support 1080p, 1080i HD encoding, etc.To solve this problem, TI introduced a development platform for the TMS320DM6467 HD codec offers a solution.TMS320DM6467 (Davinci platform) applied the C64x+ DSP chip that is provided with powerful parallel processing capabilities. With a strong computing power and various supporting peripheral interfaces, TMS320DM6467 has made itself the most suitable platform for modern digital multimedia applications. What will be completed in the essay is the studying of the H.264 algorithm and how to achieve implementation and optimization by Davinci platform.The essay includes: firstly, some common video coding standards in this field are informed. Besides, some in-depth researches have done to H.264 coding algorithm, the core technology and principle. Secondly, there is a detailed analysis of the composition and characteristics of TMS320DM6467 platform which mainly focuses on one of the ways to fulfill the application of the platform, the structural composition of DM6467 hardware platform and the designing process of the software. Thirdly, with the basic frame of analyzing and applying of three open-source coding algorithm, the design principles of the encoder are studied and the concrete ways of implementation are designed. In this part, the motion search is covered which is the largest and most complex part of in coding algorithms, for it is the main element influencing the encoder's performance. To solve the problem, motion estimation algorithm was studied in the paper to adapt to the H.264. This algorithm did a pre evaluation to the macro block of Skip and found the matching way of searching by using multi-center forecasting method to identify the most appropriate the center and analyzing the different characteristics of the image motion vector. It can be proved in the experiment that using this algorithm can significantly reduce the search points and achieve the ideal matching effect. Fourthly, the process of transplanting coding algorithms to DM6467 and the code optimization are discussed down to the last detail. Finally, the designing of the encoder can be completed on the DM6467 by making fully use of DSP hardware advantages, applying conveniently programming interface (API) and using several kinds of optimization methods to optimize the algorithms, which can improve the efficiency of the code as much as possible.